Effects Analysis of Phase Sequence Arrangement on Electromagnetic Environment in 1000 kV Same-Tower Double-Circuit Ultra-high Voltage AC Transmission Lines

Using the "Ximeng to Shandong 1000 kV Ultra-High Voltage AC Transmission Line Project" as a case study, this study focuses on comparing various indicators under both forward and reverse phase sequence arrangements to determine the most suitable phase sequence arrangement meeting electromagnetic environment requirements. Through measurements and comparisons of electromagnetic environment parameters and various indicators such as surface electric field strength of conductors, maximum surface field strength of conductors, corona inception field strength of conductors, corona inception voltage, and width of areas with field strength exceeding 4 kV/m (between the outer sides of the lines at 4 kV/m), it is concluded that the reverse phase sequence arrangement is appropriate for double-circuit lines on the same tower. This is because the reverse phase sequence arrangement for such lines can concurrently reduce tower height and transmission corridor width. It represents the optimal arrangement for conductor phase sequence and aims to offer guidance for engineering decision-makers.